Electric switch



March 8, 1932. I c, T i 1,848,853

' ELECTRIC SWITCH Q Filed March 28, 1928 Carl Thumim,

Hi5 AH'o'rne Patented Mar. 8, 1932 CARL THUMIM, OF

PATENT OFFICE PHILADELPHTA, PEN'NSYLVANLA, ASSIGNOR '10 GENERAL ELEC-TRIC COMPANY, A CORPORATION OF NEW YORK ELECTRIC SWITCH Applicationfiled March 28, 1928. Serial 110,285,890.

My invention relates to electric switches and particularly to operatingmechanism therefor. The object of my invention is the provision of animproved switch operating mechanism which is simple in construction,easy to operate, trip free throughout a wide range of its movement andis adapted to be tripped open in response to a reverse movement thereof.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawings, and

its scope will be pointed out in the appended claims.

Referring to the drawings, Figs. 1, 2 and 3 show one embodiment of themechanism respectively in switch closed position, tripped position, andresetting position.

In the drawings, the frame 1 of the mechanism is adapted to be securedto the face of a panel 2 and is shown in the form of a housing for theoperating parts. To the lower front portion of the frame is pivoted at 3the switch actuating means as the hand lever 4.- having the handle 5 andprojection 6 adapted to engage the spring detent 7 to assist in holdingthe lever in closed circuit position. Operated member 9 is pivoted tothe frame at 10 and is provided with a series of holes 11 in any one ofwhich may be pinned the rod 12 leading to the switch to be operated.Lever 4. and member 9 are connected together by means of the togglelinks 14 and 15. These links are pivoted together at 16 and are pivotedat their ends to the lever l and member 9 respectively at 17 and 18.When the lever is in the closed circuit position illustrated, pivotcenters 3, 17 and 18 are in alignment whereby little eflort isrequiredon the part of the operator to push the contacts of the switch intofully closed position. Toggle link 15 comprises a pair of plates, showntriangular in form at one corner of which is pivoted at 19 thetoggle'comprising the links 20 and 21, the opposite end of the togglebeing pivoted to the extension 22 of link 14. In the switch closedposition of the apparatus toggle links 14 and 15 are maintained in aslightly 'underset relation by the toggle links 20 and 21 which linksare held in a slightly overset relation by the engagement of anextension on link 20 with pivot pin 19. For tripping the mechanism Ihave provided an element, as the member 24 pivoted on pin 19 and havingthe projection 25 adapted to raise the extension in link 20 to cause thetoggle to buckle. Overload coil 26 has the plunger 27 connected toactuate lever 28 which in turn rocks lever 29 pivoted at 30. This lever29 is so shaped that it conforms closely to the path of movement of thecooperating end of member 24 as the mechanism moves toward the closedcircuit position thereof. The mechanism is thus rendered trip free overthat entire portion of its movement from the time the switch contactsfirst touch each other to their fully engaged position.

It is some times desirable to be able to open the switch by means of theoperating handle and when this is done the operator should besafeguarded from being subjected to a kick from the switch due to thereaction incident to a heavy load or short circuit. For this purpose Ihave provided a latching means on the operated member for automaticallytripping the mechanism in response to movement of the handle in thedirection to open the switch. This means comprises the latch 32 pivotedto member 9 and the lateral extension 33 on toggle link 21, the latterbeing constructed with the lip 34 and arranged automatically to beengaged by the latch when the mechanism is being moved from the setposition shown by Fig. 3 toward the closed circuit position shown byFig. 1. The latch is loosely pivoted to the member 9 and has the tail 36which when the member is rotated from the position shown in Fig. 3 tothat shown in Fig. 1 engages'the flanged edge thereof, the latch therebybeing held in the proper position to receive the lip 34 upon furthermovement of the member. are so constructed and arranged that the liphooks over the latch just prior to the initial connection of thecontacts of the switch. It is therefore not necessary to completelyclose the switch in order to be able to trip it open by a reversemovement of the operating handle. For example, if the switch is closedon a heavy load or short circuit the reaction of The parts the switch onthe operators hand arising from the electromagnetic forces or from gasformation in the switch is not severe since a small reverse movementonly of the handle is necessary tocause the latch to throw the toggle 20and 21 over center and release the switch. In other words, as lever 4 isrotated slightly in a counter clockwise direction, pivot 17 which issecured thereto moves in an are about pivot 3, and for a small degree ofrotation of lever 4 there is very little vertical change in the positionof pivot 17. Its movement is for the most part horizontal, with theresult that pivot 18, which is secured to the operated member 9, remainsnearly stationary. The above described movement, therefore, in effect,tends to rotate-the toggle links 14-15 as a unit about pivot 18, in aclockwise direction and thereby lower the pivot 19 secured to link 15and forming a part of toggle link 21. Accordingly, toggle link 21 andits lateral extension 33 are lowered, i. e., tend to rotate in clockwisedirection about pivot 18, while the operated member 9 remainspractically stationary. Latch 32, however, is pivotally mounted on theoperated member 9 and so cannot partake of downward movementindependently thereof. It follows therefore that as the lateralextension 33 is moved downwardly due to the initial slight rotativemovement of lever 4 towards open position, the lip 34 tends to draglatch 32 along with it, but is restrained by the latch from suchdownward movement, thereby causing rotation of toggle link 21 in aclockwise direction to buckle the toggle 2021. thus permitting theswitch to trip free of the lever 4. This construction also has theadvantage of preventing the closing of the switch in a manner some timespracticed by timid operators which results in more or less severeburning of the switch contacts. If one attempts to close the switchtoogently and after initial contact has been made vibrates the handle insuccessive elforts to get the switch completely closed the first reversemovement will cause the tripping out of the switch. This will saveunnecessary burning of the contacts and should emphasize to the operatorthe fact that the switch should be closed by a single, powerful thrustof the handle.

The switch which I have devised is provided with a visual indicator andan electric signal, both of which are not shown, for indicating to theswitch attendants that the switch has tripped out. The electric signalmay, for example, be of the well known bell alarm or horn typewhichoperates whenever the switch or one of a number of switches of a grouptrips out and stops when the tripped switchis reclosed. In the reclosingoperation some operators find that they are somewhat disturbed by theviolent ringing of a bell or the sounding of a horn and pre fer to shutoff the alarm before closing the switch. When such is done with formerapparatus there is the danger that the operator will forget to turn onthe alarm after he has closed the switch in readiness for the nextswitch that may trip out. In the switch disclosed herein I have providedan alarm contact device which will close the alarm circuit when theswitch trips open but which may be operated to open the alarm circuit bya small movement of the operating han-' dle prior to and independentlyof the switch closing movement thereof. Two fixed contacts 40 connectedin the alarm circuit are adapted to be bridged by the contact plate 41when the switch is tripped open. Plate 41 is pivotally mounted at 42 anda small weight 43 serves normally to hold the plate out of contact withthe contacts 40. Attached to the plate and the weight is the arm 44.This arm has such a length and is in such a position that in thecollapsing movement of the toggle links 14 and 15 as the switch tripsopen the intermediate pin 16'will engage the upper surface of the armand press the contact plate 41 against contacts 40, thereby closing thealarm circuit. Preferably both the arm 44 and the plate 41 areresilient, the former conveniently being made in the form of a flatspring. Fig. 2 shows the parts in the tripped position with the alarmcircuit closed. If the operator wishes to silence the alarm beforereclosing the switch he has only to swing down the handle a shortdistance which movement causes the pin 16 to further depress the springarm 44 until it slips off the end thereof when the weight 43 returns thecontact plate 41 to the open circuit position. The handle may then bereturned to the upright position if desired without reclosing theswitch, in which case the pin 16 swings below arm 44 and positivelyholds the contact plate away from contacts 40. The alarm is now silencedand although the pin 16 is now below the spring arm instead of above it,the subsequent closing operation of the switch is unaffected thereby.

I have chosen the particular embodiment described above as'illustrativeof my invention and it will be apparent that various modifications maybe made without departing from the spirit and scope of my invention,which modifications I aim to cover by the appended claims.

What I claim as new and desire to secure by'Letters Patent of the UnitedStates is:

1. A switch operating mechanism comprising an operating lever movable toa predetermined closed circuit position, an operated member, areleasable connection therebetween including a toggle, and a latchcarried by said operated member and arranged to engage said toggle whenthe lever is moved toward said position, said latch causing the terminedclosed circuit position, a member operated thereby, a releasableconnection therebetween, and a member carried by said operated memberfor causing the release of said connection when the lever is moved inthe reverse direction, said releasing member being arranged to engagesaid connection prior to the initial closing of the switch contacts.

3. A manual switch operating mechanism comprising a hand lever, a memberoperated thereby, toggle links connecting said member to said lever,said links being connected to the lever at a point spaced from thefulcrum thereof whereby the intermediate portion of the lever and saidlinks form a second toggle arranged to assume a straightened positionwhen the lever is in its closed circuit position, releasable retainingmeans for said toggle links movable with said mechanism in the switchclosing movement thereof, and tripping means therefor comprising amember shaped to conform to the path of movement of said retainingmeans.

4. A manual switch operating mechanism comprising a hand lever, a memberoperated thereby, a pair of toggle links connecting the lever to themember, one of said links having an extension thereon, a toggle betweensaid extension andthe other of said links, an element adapted to bucklesaid toggle and a tripping member adapted to engage a portion of saidelement having an engaging part shaped to conform to the path ofmovement of the engaged portion of the element.

5. A manual switch operating mechanism comprising a hand lever, apivoted member operated thereby, a pair of toggle links connecting thelever to the member, one of said links having an extension thereon, atoggle between said extension and the other of said links, a togglereleasing latch carried by said pivoted member and arranged to engagesaid Cir toggle during the movement of the lever toward its closedcircuit position, whereby a reverse movement of the lever is effectiveto cause the releaseofthe toggle.

6. Amanual switch operating mechanism comprising a hand lever, a memberoperated thereby, a releasable connection therebetween, and an alarmcontrolling means constructed and arranged to be actuated by the releaseof said connection, said alarm controlling means rendered inoperativewhile the switch is open in response to an initial switch openingmovement of the hand lever, return of said hand lever to closed positionbeing ineffective to actuate said means.

7. A manual switch operating mechanism comprising a hand lever, 11.member operated thereby, a releasable trip-free connection therebetween,an alarm switch and an operating member therefor arranged in the path ofmovement of a portion of said connection to move in one direction inresponse to the release of said connection when tripped independently ofsaid hand lever and to move in the opposite direction in response to aninitial movement of the hand lever from its closed position independentof the switch closing or resetting movement thereof.

8. A manual switch operating mechanism comprising a hand lever, a memberoperated thereby, a releasable toggle connection therebetween, an alarmswitch, and an operating member therefor arranged to be engaged by aportion of said toggle connection when the same is released to close thealarm switch, said portion being arranged to release said operatingmember when the hand lever is initially moved in a direction opposite tothat of its closing movement.

9. In a'switch operating mechanism comprising a switch operating memberand actuating means therefor, the combination of a releasable connectiontherebetween including a toggle, said connection adapted to transmitmovement from said actuating means to the switch operating member foreffecting closing movement of the switch, and a latch associated withsaid toggle for causing collapse thereof and consequent opening movementof the switch in response to reverse movement of the actuating meansduring the switch closing operation.

In witness whereof I have hereunto set my hand this 24th day of March,1928.

CARL THUMIM.

